It is desirable in some applications to cover a flat roof of a building with a waterproof membrane comprised of a rubber-like material. Such membranes are then covered with a suitable ballast such as gravel. In order to retain the gravel ballast and to control water drainage from the roof, the roof is surrounded by a gravel stop or dam. An example of such a dam is illustrated in the Hickman U.S. Pat. No. 4,071,987.
In the construction of such a roof, a sheet metal water dam-cant having a dam like configuration is secured to the edge of the roof, the water dam-cant having an upwardly and outwardly sloping surface. The watertight membrane is commonly laid across the surface of the roof and extends up the inclined surface of the water dam-cant. Means are also provided for securing the membrane to the water dam-cant. In most instances, the sheet material is secured by an adhesive to the inclined surface and may also be secured by clamps and screws extending through the membrane into the cant. One disadvantage of such prior art constructions is that the step of securing the membrane by adhesive to the inclined surface of the cant is labor intensive and time consuming. On the other hand, it is necessary that the membrane be secured to the inclined surface of the cant and particularly to the base of the inclined surface at the juncture of the roof and the inclined surface. If the membranes is not secured to the inclined surface and the membrane is subjected to tension, the membrane may pull away from the base of the inclined surface wherein it will puncture easily. Another disadvantage of prior art arrangements is that they commonly employ a screw or nail to secure waterproof material to the inclined surface portions of the cant. Such arrangements have the disadvantage that the holes formed in the waterproof material by the nails or screws may result in eventual leakage.
For reference to prior art gravel curbs, attention is directed to the Hickman U.S. Pat. No. 4,071,987; U.S. Pat. No. Re. 26,056; U.S. Pat. No. 3,731,439; U.S. Pat. No. Re. 27,761; and U.S. Pat. No. 3,719,010.